409205009 has 2 divisors, whose sum is σ = 409205010. Its totient is φ = 409205008.

The previous prime is 409205003. The next prime is 409205057. The reversal of 409205009 is 900502904.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 375274384 + 33930625 = 19372^2 + 5825^2 .

It is a cyclic number.

It is not a de Polignac number, because 409205009 - 2¹⁶ = 409139473 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (409205003) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 204602504 + 204602505.

It is an arithmetic number, because the mean of its divisors is an integer number (204602505).

Almost surely, 2^409205009 is an apocalyptic number.

It is an amenable number.

409205009 is a deficient number, since it is larger than the sum of its proper divisors (1).

409205009 is an equidigital number, since it uses as much as digits as its factorization.

409205009 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3240, while the sum is 29.

The square root of 409205009 is about 20228.8163024928. The cubic root of 409205009 is about 742.4154144897.

The spelling of 409205009 in words is "four hundred nine million, two hundred five thousand, nine".